It had to be done - a new 4" hole in my bandsaw!

Started by retired2, July 23, 2011, 09:21:58 PM

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retired2

Thirty-five years ago, when I bought the bandsaw in the following photo, no one ever dreamed of dust collection in a small shop as we know it today.  All you hoped for was a dust chute that put most of the dirt in a neat pile on the floor so it could easily be swept up.  Powermatic's idea of a dust chute on their 14" bandsaw was a 2" pipe stuffed in the throat just below the table top.  It captured about 50% of the dirt - the rest accumulated inside the saw until it started coming out every crack until there was dirt everywhere.

When I got my Delta 50-760 DC I figured this would be the easiest tool in my shop to contain the waste - NOT!  I really didin't expect my first attempt to work because I just hooked the full force of the DC to the 2" pipe and hoped for the best.  It sucked up the 50% of the dirt that the chute previously sent to a neat pile on the floor, but the other 50% still went everywhere.

So, I thought about the problem for days until finally I decided I needed a new dust port, a real one.  So, I took the steel door off the bandsaw and took it to a local fab shop and asked if they could burn a neat 4" hole in the door where I had marked it.  The guy I deal with said no problem.  He could see the pain that cutting a hole in my bandsaw was causing me so he advised me to take two aspirin and come back in the morning with several dozen assorted donuts for the guys in the shop.  That's all it cost me.  They did an nice job, but I spent the next few days recovering from the surgery.

This is a photo of my finished installation, but not the end of the story:



Once the two dust hoses were connected as shown in the above photo, dirt was still escaping around the throat just below the table top.  The lower blade guides were the problem.  They form two 45 degree ramps that were deflecting the dirt coming out of the blade gullets.  Here's a picture before my modification.



Now I had to figure out a way to capture the deflected dirt and redirct it to the 2" dust chute immediately below.  The solution was a small box that snugs up to the underside of the table and wraps around the blade and lower guides.  This keeps the dust from escaping the vacuum stream below.  Here's two photos showing the box and how it is attached.






So, here's the lesson.  If you've got an old bandsaw that throws sawdust around in spite of being connected to a good DC, cut a real port in a strategic location, and everything will work much better.  Take my word for it, you and the bandsaw will live through it!!

pitbull

Nice work. I like the hammered green paint job as well.

How well does the little 2" line suck. I know you have it on a wye...I was considering adding something like this for a dust hood, but fear the dust collector can not give me enough airspeed to pull dust from the 2" line.

retired2

#2
Quote from: pitbull on July 24, 2011, 02:27:05 PM
How well does the little 2" line suck. I know you have it on a wye...I was considering adding something like this for a dust hood, but fear the dust collector can not give me enough airspeed to pull dust from the 2" line.

Well, it does what it needs to do, but it is a little on the weak side.  Now, I need to qualify that response.  My bandsaw is nearly 40 ft. of 5" pipe away from my Delta 50-760 DC, and that's not counting the equivalent losses for ells and laterals that are in the run.  That puts me close to the limits of what my DC can do, and I still don't have a Thein separator installed.  I'm keeping my fingers crossed.

The wye you see in the photo is also a reducer.  It is a 5"x4"x3".  The 3" branch has a plastic reducer (3" x 2-1/2"), so the flex hose is 2-1/2" to the bandsaw.  At the bandsaw it reduces to 2".

My advice to you would be give your idea a try.  As long as the area of the two branches doesn't exceed the area of your drop line, you should get some benefit, but if you are starting with a 4" line, I'm not sure your going to get the kind of air flow you need if you split it further.

Regards


 

pitbull

I was going to be coming of a 6" line and splitting it into a 4" and 3" then down to 2-1/2". I have run previous tests with a 2" line and all have been unsatisfactory. However, I was just wondering if you got different results. I think for the small ducting like that I will stick with a shopvac.

Thanks

retired2

Quote from: pitbull on July 25, 2011, 06:01:57 AM
I was going to be coming of a 6" line and splitting it into a 4" and 3" then down to 2-1/2". I have run previous tests with a 2" line and all have been unsatisfactory. However, I was just wondering if you got different results. I think for the small ducting like that I will stick with a shopvac.

Thanks

If your application is a piece of equipment that you only plan to have one 2" connection, I would agree a shop vac would be much better than a DC. 

In the case of my bandsaw, the 4" connection is doing 90% of the work and the 2" is just catching a few fines that ordinarily might get away.  I'm not sure what the SP is for your shop vac, but typically they can run nearly 8-10 times the SP of a dust collector.

retired2

#5
And now for the rest of the story....

I realize this is a very old thread, but a question came up in another thread that led me to think I should post the final outcome of my bandsaw DC story.

In a previous post I was asked how the 2" port on my bandsaw was working.  My response was that it was a little weak and I had not yet installed my separator.  Well, after the separator was installed, I was not happy with the performance of either port.  I decided the best thing would be to close the small port just under the table and give all the air to the 4" connection.  That is what I did, and it works better.  It is not great because as I explained earlier this tool is a long way from my DC.

When I disconnected the smaller hose, I decided to retain it for general purpose vacuuming in the area.  But to do that I had to add blast gates to each leg of the lateral so the hoses could be operated independently.  Here is a photo of the current setup:






Clark Savage Jr

Ok, I had a 4" and a 2" - still had issues.

But changed my 2" to a hose with a common rigid nozzle - CLOSED the end of it and cut a slot in the side in line with the area to get ABOVE the blades.

The 4" does all the collection, the 2" keeps my blades/guide clear.

Works great, saves my bearings and put the suck where it needs to be.............

see pics

retired2

I'm guessing from the photos that when you are running the bandsaw it is pretty close to the DC.  That would make a world of difference for me, but unfortunately my tools are all stationary, as is the DC, and in the case of the bandsaw, way too far apart.

Clark Savage Jr

If you are speaking about mine - yes, not 40 feet - that's a long, long way. I feel for you.

But if you consider 40' of pipe and you apparently are still collecting the dust, then my spiral with eleven feet internal with less than 10' of run to any of my equipment equates to less than your simple pipe run. That makes a difference for me. I would add the internal of the spiral is smooth walled and area compensated - not enough to be a "free flow" air column calculation but enough to outflow the restriction in a vacuum situation versus my fan abilities - and larger area than my fan inlet. Yes, keeping up speed is not as important in that situation. I should not post this here, but you bring up some relevant information about friction and such. Just opening the airways. I will side post this in my other:

Proposed Spiral Build - why - and a few of my observations

I hope since your post about 40' was a long time ago you have been able to rectify the distance issue. I too have issues, not being distance related.

Throwing my bandsaw pics out was actually for others, not the Powermatic, note I plugged my ineffective 2" port and moved it above my lower guide bearing setup. This was due to dust collecting on and above the bearings before ever getting to the port below them - I was buying bearings in twenty packs due to that fact and replacing them every five days as they seized regularly. Now, they last about a month. Yes, I only use a 4" that is split for both ports and it works great. I also restricted my 4" port by experimenting with the required flow - posting pic of that. Made a big difference. I do not know if you still full flow your 4".

Hope this helps someone else that finds themselves in the same situation as I found myself.

retired2

Quote from: Clark Savage Jr on February 08, 2016, 08:40:15 AM
If you are speaking about mine - yes, not 40 feet - that's a long, long way. I feel for you.


I said bandsaw when I meant to say your table saw.  Sorry for that confusion.  And no I did not resolve my 40' problem.  That only resolution to that problem is buy a higher powered DC, and I simply can't justify the cost or additional space required.  I'll just live with what I have.  It is just one tool, and it works well enough to get the vast majority of the dirt.